N-amino tetrahydrothiazine derivatives, also termed N-substituted thiomorpholine, such as nifurtimox are the mainstay drug therapy for Chagas disease, caused by a protozoan parasite (Trypanosoma cruzi).

Nifurtimox has recently been reported to have an anticancer therapeutic activity. However, nifurtimox and other nitro derivatives reportedly have a low efficacy of cancer cell inhibition.